How many national marine sanctuaries are there?

As of October 2023, there are 15 national marine sanctuaries in the United States. These protected areas are designated to conserve marine ecosystems, historic shipwrecks, and cultural resources. Each sanctuary is managed by the National Oceanic and Atmospheric Administration (NOAA) to promote research, education, and sustainable use of marine resources. The sanctuaries vary in size and ecological significance, spanning diverse habitats across the U.S. coastline.